Reaction vessel with coil contact heat exchange



United States Patient 3,523,761 REACTION VESSEL WITH COIL CONTACT HEATEXCHANGE Ward A. Graham, Kansas City, Mo., assignor to StratfordEngineering Corporation, Kansas City, Mo., a corporation of DelawareFiled Oct. 4, 1966, Ser. No. 584,264 Int. Cl. F28f 13/06 U.S. Cl. 23-2856 Claims ABSTRACT on THE DISCLOSURE A circulating reaction vesselutilizing a circulation tube and including heat exchanging meanswherein: (1) the heat exchanging means is itself a portion of thecirculation tube, (2) the portion of the heat exchanging means which ispart of the circulation tube comprises a wrapped coil with adjacentcoils spaced, one from the other, to permit passage of limitedquantities of fluid therebetween" and (3) variations of structure of thecirculating tube coil are provided in order to achieve flow managing andcontrolling effects.

This invention relates to apparatus for circulation mixing processing ofliquids or liquids and finely divided solids and refers moreparticularly to such apparatus wherein temperature control of thecontents of the vessel is greatly important.

Analogous circulating tube reaction vessels may be seen in the patentsto Webb et al., 3,027,242, issued Mar. 27, 1962, for Concentric Injectorfor Circulating Tube Reactor, the patent to H. W. Stratford, 2,909,534,issued Oct. 20, 1959, Vertical Contactor With 'Features, the patent toH. W. Stratford, 2,840,355, issued June 24, 1958, for Mixing Vessel. Thepatent to D. H. Putney, 2,800,- 307, issued July 23, 1957, Apparatus forControlling Temperature Change of Blends of Fluids or Fluids and FinelyDivided Solids is also pertinent. The latter and the earlier mentionedpatents are particularly directed to horizontal types of circulatingvessels, while the second and third patents are vertical vessels, withwhich the present invention is concerned.

An object of the instant invention is to provide a circulating reactionvessel employing a circulation tube and heat exchanging means wherein-(1) The heat exchanging means is itself a portion of the circulationtube,

(2) The portion of the heat exchanging means comprising part of thecirculation tube comprises a wrapped coil with adjacent coils spaced,one from the other, to permit passage of limited quantities of fluidtherebetween,

(3) Variations of circulating tube coil construction are provided toachieve certain flow managing and controlling effects.

Other objects of the invention include the modification of a heatexchanging vertical circulation tube containing contactor utilizing aWrapped coil wherein greatly increased heating rates and working of thecirculating materials are accomplished.

Another object of the invention is to provide a greatly improved mixingvessel for use in processes such as grease or soap manufacture whereincontinuous working of the product is achievable during heating and/orcooling of same, whereby to improve yield and stability of the product,wherein better working of the product is achievtable than in previouslyavailable systems due to additional shear application thereto andwherein greatly improved heat transfer during heating or cooling isachievable to the unique structure of the mixing vessel.

3,523,761 Patented Aug. 11,, 1970 Other objects of the invention includeprovision of mixing apparatus able to meet the most demanding heatingand cooling cycles for grease manufacture, said apparatus alsominimizing the possibility of spontaneous ignition and thereby providingmeans for producing greases most economically.

Other objects of the invention are to provide highly efficient mixingmachines and devices in which the materials charged to the mixer arerapidly and uniformly mixed and dispersed and then maintained in acontinuous state of agitation and circulation, a multiplicity of pathsof circulation of varying length being provided for return from parts ofthe circulation tube to the impeller.

Another object is to provide an advanced and improved mixing vessel foruse in grease production which will markedly aid in the production ofmore and different types of soap stocks and some finished greases, suchas, soda, lime, aluminum, barium, lithium, mixed-base and neweracetate-complex soaps.

Other objects of the invention include providing a circulating mixingvessel having maximum efiiciency of internal circulation and heattransfer within the unit, wherein there is provided close control andadjustability of the heating system, whereby same can be maintained at afixed level above the required critical temperature of soap in process,wherein near instantaneous mixing is provided of maximum benefit inpromoting chemical reaction and also continuous circulation whichpromotes heat transfer and wherein improved means of removing volatilesare provided, as well as a vessel which permits a greater variation inthe amount of material any one contacting or mixing vessel can itselfhandle.

Other and further objects of the invention include, in the manufactureof grease stocks and soaps, as well as greases per se, the productionand obtaining of finer soap particles, whereby to obtain more powerfulgelling action, wherein more eificient use of the material charged tothe reactor is achieved by the fine subdivision and dispersion ofparticles in the desired lattice-like structure, thereby to obtaingrease with better flow properties and finer fibers.

Additional objects include the provision of a circulating and workingvessel for greases wherein the elimination of batch losses requiringreworking is achieved, rapid and complete saponification of the variousalkali metal soap stocks is obtained, significant savings in the cost ofingredients and the time required to produce the common soap bases usedin the grease industry are achieved and thus the production of uniform,finely divided soaps is promoted.

Another object of the invention is to improve heat transfer by inductinggreater and greater varieties of turbulence in same across heat transfersurfaces spaced various distances from the impeller.

Another object is to provide a contacting circulating heat exchangevessel which utilizes a spaced, wrapped heating coil which isself-cleaning; that is, after the soap has been blown out of the vessel,oil may be circulated which will entirely clean the coil.

Other and further objects of the invention will appear in the course ofthe following description thereof.

In the drawings which form a part of the instant specification and areto be read in conjunction therewith, embodiments of the inventiveapparatus are shown and, in the various views, like numerals areemployed to indicate like parts.

FIG. 1 is a side, partly sectional view of a vertical contacting vesselembodying the instant invention.

FIG. 2 is a view taken along the line 22 of FIG. 1 in the direction ofthe arrows.

Aug. 11, N70 .w. A. GRAHAM REACTION VESSEL WITH COIL CONTACT HEATEXCHANGE Filed 001;. 4, 1966 s a mm m N N w .4 n N K, A

Ward 4. fi/ a/mm to 415 F. Steam over the circulating liquid may bevented to atmosphere. The temperature levels off and circulation is in avery fluid state.

A'vacuum may be pulled at the top of the vessel. The remaining oil isnow added at ambient temperature to a level over the coil. Condensate(steam) is run through the coil. As the temperature drops incirculation, the soap crystals form and are worked through the gaps.There is a minimum temperature to work any batchas defined by thebridging viscosity for the given coil gap. At this, circulation throughthe gap ceases and the impeller cavitates. At most, the coil steamtemperature is held slightly below bridging temperature. Thereafter thesoap is blown out of line 11 to the finishing kettle. Oil cleaning withor without heating follows with removal of oil through line 11.

From the foregoing, it will be seen that this invention is one welladapted to attain all of the ends and objects hereinabove set forthtogether with other advantages which are obvious and which are inherentto the structure.

It will be understood that certain features and subcombinations are ofutility and may be employed without reference to other features andsubcombinations. This is contemplated by and is within the scope of theclaims.

As many possible embodiments may be made of the invention Withoutdeparting from the scope thereof, it is to be understood that all matterherein set forth or shown in the accompanying drawings is to beinterpreted as illustrative and not in a limiting sense.

Having thus described my invention, I claim:

1. A mixing device comprising an outer enclosing shell,

a circulating tube positioned within said outer shell and spacedinwardly therefrom concentrically and longitudinally,

an impeller positioned within said circulating tube,

driving means for said impeller,

an output opening in said shell, said shell and circulating tubevertically positioned,

at least the uppermost portion of said circulating tube comprising ahelical wrapped coil, the successive wraps of said coil so spaced fromone another as to provide an elongate helical gap whereby fluidscirculating within said vessel around said circulating tube pass throughsaid gap,

the inlet and outlet connections to said coil entering and leaving saidshell below the topmost level of said coil.

2. A mixing device comprising:

an outer enclosing shell,

a circulating tube positioned within said outer shell and spacedinwardly therefrom both concentrically and longitudinally,

an impeller positioned within said circulating tube,

driving means for said impeller,

an output opening in said shell,

said shell and circulating tube vertically positioned,

at least the uppermost portion of said circulating tube comprising ahelical wrapped coil, the successive wraps of said coil so spaced as toprovide an elongate helical gap whereby fluids circulating within saidshell and around said circulating tube pass through said gap,

the uppermost wrap of said coil sealed against the inner surface of saidshell whereby to prevent fluid flow above said uppermost wrap from theannulus between said coil and shell.

3. A mixing device to forceably circulate fluids with coil contact heatexchange, said device comprising:

a vertically positioned, outer enclosing shell,

a circulating tube of essentially three-piece, unitary constructionvertically positioned within said outer shell and spaced inwardlytherefrom both concentrically and longitudinally whereby to provide anouter annulus between said shell and said tube and a central passagewayinwardly of said tube for continuous circulation of fluids therearound,

said circulating tube having a lower portion thereof of lesser innerdiameter of cylindrical shape, an intermediate portion of invertedfrusto-conical shape surmounting said lower portion, and an uppergreater internal diameter portion substantially cylindrical in shape andsurmounting said intermediate portion,

an impeller concentrically positioned within the lower portion of saidcirculating tube to sweep substantially the cross section thereof andoperable to circulate fluids,

driving means for said impeller,

an output opening in said shell,

the upper portion of said circulating tube comprising a single helicalwrapped coil in which the successive wraps of said coil are sovertically spaced as to provide therebetween an elongate helical gap,whereby a substantial portion of all fluids circulating around saidlower and intermediate portions of said circulating tube are forced inlateral circulation through said helical gap,

said successive wraps of said coil also so spaced as to require fluidcirculation to and through at least substantially the uppermost portionof the gap as well as through the lowermost portion of said helical p,

at least the lower portion of said circulating tube being imperforate.

4. The device as in claim 3 wherein each of the successive wraps towardthe upper end of said coil increases in diameter, thus incrementallydecreasing the annulus between said shell and circulating tube in anupward direction.

5. The device as in claim 3 wherein the vertical distance between thesuccessive wraps of said coil increases in an upward direction from saidintermediate portion of the circulating tube.

6. The device as in claim 3 wherein the intermediate portion of saidcirculating tube is imperforate.

References Cited UNITED STATES PATENTS 2,071,624 2/1937 Graham 1082,367,149 1/ 1945 Smith 165109 X 2,577,856 12/1951 Nelson 165108 X2,800,307 7/1957 Putney 165108 3,288,567 11/1966 Graham 23-28833,302,700 2/1967 Dugan 165109 MORRIS O. WOLK, Primary Examiner S.MARANTZ, Assistant Examiner US. Cl. X.R. 165108; 259-8

